Fuse



April 7, 1925. 1,532,368

F. w. BOLD FUSE Original Filed Oct. 31, 1919 2 Sheets-Sheet 1 Fig.3.Eiyi.

A m 5 5 Q/ a a as April 7, 1925.

F. w. BOLD FUSE Original Filed 060%1919 6g 6 2 Sheets-Sheet 2 PatentedApr. 7, 1925.

UNITED STATES PATENT QFFICE.

FREDRICK W. BOLD, OF CHELSEA, MASSACHUSETTS, ASSIGNOR TO CHARLES H.PEARSON, OF BR OOKLINE, MASSACHUSETTS.

rusza Application filed October 31, 1919, Serial No. 334,849. RenewedJuly 1, 1924.,

To all whom it may concern:

Be it known that I, FREDRICK W. BOLD, a citizen of the United States,and resident of Chelsea, in the county of Suffolk and State ofMassachusetts, have invented an Improvement in Fuses, of which thefollowing description, in connection with the accompanying drawings, isa specification, like letters on the drawings representing like parts.

My present invention relates to mechanical time fuses, and moreparticularly to mechanical time fuses adapted to be applied to ordnanceshells for the purposev of deto nating the charge therein after apredetermined length of time following the discharge of the shell from.a gun.

In fuses of this character, no great difiiculty has been experienced inthe past in satisfactory, must be safe to handle with thedevising meansto positively detonate the charge in the shell. Considerable difliculty,however, has been experienced indevising means that will admit of thecharge being detonated at exactly the right time, that is, means thatwill. detonate the charge when, and only when, it should be detonated.In other words, a mechanical time fuse, to be assurance that nothingshort of its discharge from a gun, or by dropping it from such adistance that the shock on impact will be equal to its discharge from agun, or an equivalent shock, will place the mechanism of the fuse inoperative position, or in condition to detonate the charge of the shellto which it may be attached.

Mechanical time fuses of this character must be strong enoughmechanically to withstand the shock of'discharge and the tremendouscentrifugal forces set up by the rotation of the shell after discharge.That such strength is essential will be obvious when it is understoodthat the shock of discharge is so great that it is generally acceptedthat the inertia of "each grain of weight of the fuse becomes equal toapproximately two pounds; that is, the apparent weight of the fuse isequal to its actual weight multiplied some fourteen thousand times. Thecentrifugal force set up by the rotation of the shell is such that at adistance of 'approximatel five-eighths of an inch from the axis 0 thefuse such centrifugal force is approximately equal to the force due tothe shock of firing. Notwithstanding the tremendous forces set up by theshock of firing and the rotation of the shell, the moving parts of thetimingmechanism should run accurately withinvthe one-hundredth part of asecond, since with a velocity of more than a thousand feet per second,an error in the timing of the fuse may make a tremendous difference inthe results attained. The carrying, or what may be termed the stationaryparts of the fuse, must be therefore, of such ri id character as to beimmune from the e ects of both shock and centrifugal force, while themoving elements, such as the time train and escapement, must be light inweight to run freely and without binding, as must also the firing pinand release mechanism therefor.

As a time fuse, when attached to a shell, has its time train always inoperative condition, it is essential that means be provided to preventaccidental starting of such time train, with the resulting disastrouseffects, until the desired predetermined length of time after such'starting.

An object of my present invention therefore, is the provision of meansassociated with the time train, to prevent the starting of the timingtrain until the fuse has been subjected to the shock of firing.

As however, a shell with a fuse attached, may be subjected to a shock,other than the shock of firing, and which shock may be equal to theshock of firing, it is essential for safety that an additional safeguardhe provided that will prevent premature detonation of the charge of theshell because of such accidental shock.

Another object of my'invention, therefore, is the provision of meansthat will positively prevent premature detonation of the charge of theshell because of'shock other than that caused by the firing of the shellfrom the gun.

In carrying out the above object, I provide a spring pressed pivotallymounted shutter or plate in the path of movement of the firing pin,which plate is retained in position to prevent. axial movement of thefiring pin until the centrifugal force generated by the shell in itsrotation exceeds a predetermined amount. This amount is determined by aproper proportioning of the spring used to retain the plate in its tweenthe firing pin and the primer, and

associated" with said means a device which must be subjected tosubstantially the equivalent of the shock of firing before the meansabove referred to can be rotated to expose the primer to the action ofthe firing pin.

A further object of my invention, is the provisionof means associatedwith a centrifugally operated safety device interposed in the path ofmovement of the firing pin, for positively preventing the prematuredischarge of the shell due to accidents in handling and shipping.

As stated above, the time train of the fuse is always in operativecondition; thatis,

the driving mechanism, usually, a spring, is

wound up, and the time train is started by the shock of firing. Thetimeatwhich the charge of the shell is detonated after the shell isfired from the gun varies with the range of the object fired at, so thatusually this time interval is determined j'ust prior to the insertion ofthe shell in the gun, and in accordance with the range given-by the menin charge of "the range finder. Means must be provided therefore, foraccurately determining this time interval, and it is usual to provide agraduated rotatable setting cap or head on thefuse block, geared to arotatable plate on the time train. Various expedients have been employedfor gearing the cap to the rotatable plate, and also for gearing therotatable plate to the time train, none of which have been entirelysatisfactory.

A further object of my invention therefore, is the provision of improvedmeans for gearing the cap or head of the fuse to the rotatable plate onthe time train that will positively couple these two elements -to-.

gether to set the time train to release the firing pin after apredetermined length of time, and which will operate to positivelyrelease said plate from the cap or head un der the shock of firing.

In carrying out this last named object, I provide a spring attached atone end to the interior of the setting capor head, with the free end ofsuch spring under tension and always tending to move against theinterior of said ca or head into position to release the rotata leplate.Slidably mounted on said spring. is a weight which engages with theinterior of the cap or head and holds the free end of the spring inengagement' with the rotatable plate on the time train. A notch in thespring ordinarily prevents movement of said weight towards the free endof the spring, the force of the shock of firing, however, being greatenough to cause said weight to move past the notch and into position,and to be held there, to allow the spring to release the retatableplate.

A still further object of my invention is the provision of means forpositively connecting the rotatable plate with the timing trainsimultaneously with its release bythe spring above mentioned.

In carrying out this object, I attach said plate positively to thecenter staff of the time train, which staff is made tapering for' aportion intermediate its ends. On this tapered portion I mount the hubofone of the gears of the time train, this mounting being such that thestaff may be freely rotated during the setting of the time interval asabove described, While providing a positive means for locking the staffand hub together by the shock of firing.

The setting of the timing train is a delicate and important operation,and in order that the best results may be obtained, I have providedimproved means for mounting the setting cap or head on the fuse block insuch a way that the power required to turn said cap may be varied tosuit the convenience of theoperator. To this end I provide acircumferential groove in the fuse block and mount therein a spring ringover which the cap or head may be forced, and vary the tension of saidspring ring by a screw or screws passing through the cap or head andengaging with the spring ring.

As it is frequently necessary to reset the timing mechanism, and as thisoperation has always been attended with great risk, owing to the factthat the notch in the setting plate or disc is'moved in this operation,into registry with the release lever of the trigger, I have so devisedthe setting spring in the setting capthat the tooth on the settingspring entirely blocks the notch and absolutely pxrevents the entranceof the release lever. y this means, the timing mechanism may be set andreset repeatedly without danger. a

O-her novel features of construction and arrangement of parts willappear as the description of the invention progresses.

In the accompanying drawings illustrating the preferred embodiment of myinvention,

Fig. 1 is an elevation;

Fig. 2. is a sectional elevation;

Fig. 3 is a plan view of the fuse block on the line 3--3 of Fig. 2showing the construcbut vice

. of the clock train startin Fig. 4 is a plan view showing the timingdisc and associated mechanism in position on the-fuse block;

Fig. 5 is a detail showing the construction of the connection betweenthe stafl and the hub of the timing train;

Fig. 6 is a sectional plan view, taken on the line 6-6 of Fig. 2;

Fig. 7 is a sectional plan view, taken on the line 7-7 of Fig. 2;

Fig. 8 is a sectional plan view, taken on the line 88 of Fig. 2;

Fig. 9 is a fragmentary side elevation of the timing train, taken on theline 99 of Fig. 4;

Fig. 10 is a detail taken on the line 10- 10 of Fig. 9;

Fig. 11 is a detail showing a modification mechanism; and

Fig. 12 is an enlarged detail showing the modification of the clocktrain starting mechanism illustrated in'Fig. 11.

Fig. 13 is an enlarged sectional detail, showing the construction andarrangement of the positive lock for the pivotedsafety plate.

Referring to the drawings, 10 designates the fuse block, providedwithexterior threads 11 by means of which it may be attached to a shell, andwith a priming chamber 12 on its lower end, this chamber being closed bythe screw plate 13. A passage 14 extends from the priming chamber 12 toa depression 15, located in the upper portion of the fuse block 10 andin which is placed the primer 16. The upper face of the fuse block isrecessed at 17 to receive the lower plate 18 of the clock or timingmovement 19. Screws 20 hold the movement firmly in position in suchrecess. A portion of the bottom face of the recess 17 is cut away toform a' chamber 21 exposing the upper portion of the depression 15, inwhich is located the primer 16. Pivotally mounted on the lower face ofthe chamber 21 is a plate or shutter 22, held in normal position, or inthe position to cover the depression 15, by a spring 23 secured in thechamber -21 by the screw 24. Referring particularly to Figs. 3 and 13,81 designates a hole in the base 10, said hole being parallel to andspaced apart from the passage 14. The lower end of this hole81 istapered as shown, to correspondwith. the taper 86 on the lower end ofthe pin 85 which pin has afree sliding fit in the hole 81. The upper endof the'hole 81 is counterbored or re cessed at 82. The pin 85 isprovided, near its upper end, with the circumferential groove 87 inwhichis fitted a'spring ring 88, this ring bearing against the bottom ofthe counterbored portion 82 and normally hol'din the upper end of thepin 85 in the path of movement of the pivotally mounted plate or shutter22, as clearly shown in Fig.-

lock or stop for the pivoted plate, preventing said plate from beingmoved to expose the primer 16 until after the pin 85 is moved downwardinto the hole 81. As this can only occur when the shell is subjected tothe shock of firin the pin is an absolute safety device, and tl re shellmay be handled. with impunity. When the shell is fired, the pin 85 isforced into the hole 81, the spring pin in this movement being forcedupward on the pin, and the taper end 86 of the pin wedges into the taperof the hole 81, looking the pin 85 out of the path or rotation of theplate 22.

The clock or timing movement 19 ,comprises the bottom plate 18, middleplate 25, and top plate 26, spaced apart from each other by a pluralityof pillars 27 and 28 respectively, and a cover plate 29 is secured tothe top plate 26. The center staff 30 is mounted in bearings in themiddle-plate 25 and cover plate 29, and the intermediate portion of thestaff is tapered, as clearly shown in Fig. 5. Mounted on the taperedportion of the staff, and ordinarily rotatable with respect thereto, isa hub 3d, at the bottom of which is staked, or otherwise secured, a gearwheel 35 meshing with a pinion 135 associated with the portion of thetiming gearing located below the-middle plate 25. As the constructionand arrangement of such portion of the timing gearing forms no partofthe present invention, it will not be described in detail herein. Onthe hub 34 and above the gear wheel 35 is staked an arm or release lever33, which extends laterally from the hub and is rotatable therewith, theend of the arm in its rotative movement engaging, ordinarily, with thefree Weighted end of the stop 32 riveted, or otherwise secured to thebottom of the top plate 26.

The top plate 26 is recessed at 36 to provide a chamber for the drivingspring 39 of the timing mechanism, and the upper portion of the hub 34is squared or otherwise machined out of round to provide a holding meansfor the non-cylindrical passage in the inner spring bearing 38. Theinner end of the volute spring 39 'is attached to the bearing 38, whilethe outer end is attached tothe annular ring 40, the lower end of which,together with the spring 39, fits into the recess 36. The upper outerperiphery of the ring 40 is provided wit-h gear teeth 141 and by'meansof which the'spring is wound up, a suitable tool being used inconnection therewith for this purpose. Pivotally mounted on the upperface of the top plate 26 is an improved spring pawl 75, the cover plate29 being cut away, as shown in Fig. 7, to form a housing therefor. Thecut away portion of the cover plate 29 is so proportioned with respectto the pawl with the center staff 30, the action of cen- 1 trifugalforce acting on the pawl as theshell is rotated, is reducedto a minimum.'Further, there is no danger of the pawl breaking and releasing thedriving spring 39 un-' der the centrifugal force exerted by the .shellin its rotation as the working tooth of the pawl is supported throughoutpractically its entire length by the cut away portion of the cover plate29.

Staked to the upper end of the staff is a setting plate 62, provided onits periphery with a notch 67 into which the extension 68 of the releaselever 69 moves to release the firing pin 41. The firing pin slides inbearings in the top and bottom plates 26 and 18 respectively, and isprovided, intermediate its ends, with an integral collar 42, which formsnot only an abutment for the firing spring 43, but a sear for thetrigger 44 on the rotatable shaft carrying the release lever 69. Byreferring to Fig. 10 it will be noted that the trigger 44 is bevelled orrounded in order to facilitate rotation of the shaft 45 by the firingpin 43- when the notch 67 registers with the extension 68 of the releaselever. Slidably mounted in the plates 25 and 26 is a pin 31, providedwith a collar intermediate its ends, and the upper end of this pin 31lies normally in the path of movement of the end of the release lever69, adjacent the extension 68 thereof, and prevents the extension '68from. engaging with the periphery of the setting plate 62. The shock offiring causes the pin 31 to move downward, as viewed in Fig. 9, movingthe upper end out of engagement with the release lever 69, and allowingthe extension 68 to engage the setting plate 62.

The clock or timing movement 19 -is placed in position in the recess 17,so that the firing pin 41 is in alinement with the depression 15, inwhich is located the primer 16 and is held in such position by thescrews 20.

The upper outer portion of the fuse block is cut away at to provide abearinu surface for the setting cap or head 51. 6n the vertical face ofthe cut away portion 50 is an annular groove 52, in which is placed aring 53 of spring metal. The outside diameter of this ring 53 whenexpanded, is

. greater than the internal diameter of the lower portion of the settingcap or head 51,

'said cap or. head to be forced over the ring 53 and into the positionshown in Fig. 2.

A plurality of screws 54 pass through the setting cap or head 51 andengage with the ring 53 to alter the tension thereof. The power requiredto turn the cap or head51 during the setting operation may be thusvaried to suit the convenienceof the operator.

On the interior wall of the cap or head 51 is attached, in longitudinalgroove 76, by the screws and nuts 55Iand 56 respectively, a fiat spring57, provided with a notch 58, struck up from the metal of the spring.The lower end of the spring 57 is provided with a tooth 59 which engageswith and completely spans a notch 60 in the setting plate 62 and alsoengages with the spring plate 61 secured to the setting plate 62, whichin turn is positively secured to the staff 30. The sprlng 57 is sotensioned as to tend to move intoengagement with the interior wall ofthe cap or head 51, and thus disengage the tooth 59 from the notch 60,and is normally prevented from doing so by the movable weight 63 which.is positioned on the spring and above the notch 58. This weight 63 isforced by the spring 57 into the depression 77 in the interior wall ofthe cap 51. Under the above conditions, the setting cap or head 51, whenturned, will rotate the setting plate 62, which may thus be moved intoany desired position, the amount of such movement being noted by thegraduations 64 on the lower'periphery of the setting cap or head 51 inconnection with the zero mark on the periphe of the fuse block.

In or er that the position of the settin plate 62 may be positivelydetermined, have provided a peek hole' 65 in the side wall of thesetting cap or head 51, which peek hole is in alinement with the tooth59 on the spring 57. A flat screw 66 normally closes' the peek hole 65,and when in position, the outer surface of said screw is flush with theouter surface of the cap or head 51.

The operation is as follows, it being assumed that the fuse block andassociated parts are attached to a shell, that the opcap or head isfunctioning properly, he removes the fiat screw 66 from the peek hole 65and, by observing the condition of the mechanism, reassures himselfregarding this point. The rotation of the setting cap or head 51 causesa corresponding rotation of the setting plate 62, due to the fact thatsuch plate and cap are positively coupled or geared together by thetooth 59 of the spring 57 engaging in the notch 60 of the plate 61. Suchrotation of the setting plate 62 moves the notch 67 therein relativelyto the upward extension 68 of the release lever 69, and altering thetime necessary for said notch 67 to come into operative position with-)respect to said extension. 68. If now, the

hell is fired from the gun, the shock of firing does several things 5 itcauses the pin 31 to move towards the middle plate 25 and allows theouter end thereof to disengage itself from the end of the release lever69 the extension 68 of said release lever 69 engages with the peripheryof the setting plate 62; the free weighted end of the stop 32moves-downwardly and frees itself from the end of the stop lever 33 ofthe timing mechanism-this stop being of dead as distinguished fromspring metal, remains in its downward position-this operation allows thetiming train to start; the pin 85moves downward in the hole 81 out ofthe path of rotation'of the plate 22 and wedges itself on the taper 81;the weight 63 is forced downward, as viewed in Fig. .2, past the notch58 and the spring 57, moving outwardly toward the interior wall of thecap or head 51, causes the disengagement of the tooth 59' from the notch60the setting cap is now free to rotate; the hub 34 is forceddownwardly, as viewed in Fig. 5, and is rigidly clutched to the staff30, the tapering form of the staff and passage in the hub 34 assistingin such clutching operation the setting cap 62 being fast to the staff30, is now rotated by the timing train.

All of the above operations occur instan-' taneously and simultaneously,the result being that the timing train and the setting plate 62 begintheir rotation at the same instant and the time "of the release of thefiring pin is measured from that instant. As the shell leaves thechamber of the gun, it takes the rifling, rand v in consequence israpidly rotated. When the centrifugal force generated by such rotationis equal to or exceeds a certain predetermined amount, the pivoted plateor shutter 22 overcomes the tension of the spring 23 and moves to aposition to expose the primer. After the timing train has rotated thesetting plate 62 sufiiciently to cause the notch 67 therein to registerwith the extension 68 of the release lever 69, the tension of the firingspring 43 is suflicient to cause, by means of the collar 42 and bevelledtrigger 44,- the rotation of the shaft 45, and' the release of thefiring pin 41.

From the above, it is obvious that until the shell is set in rotation bythe rifling of and 29 the cover plate in which plate is rotatablymounted the center .stafi 30. Secured to the hub 34 is the radiallyextending arm 33, which, as described in connection with Figs. 5 and 8,is normally in engagement with and is prevented from moving by, theweighted arm 32. As a substitute for the Wei hted arm 32, I may providea rod or shaft 0 mounted parallel to the staff 30 in the top and bottomplates 26 and 25 respectively. This rod or shaft 70 is provided near itslower end, with a tapered. portion 71 and slidably mounted on the rod orshaft 70 is a sleeve 72, the lower portion of the bore of which istapered to correspond with'the taper 71 on the rod or shaft 70. Theupper portion of the sleeve 72 is'groovedat 73 which engages with theouter end of the arm" 33. The sleeve 72engaging with the arm 33,prevents said arm, and therefore the timing train, from rotatin whilethe arm 33 engaging .in the groove 73, prevents, under normalconditions, the separation of the sleeve and arm. When the shell isfired from the gun, the shock of firing forces said sleeve downwardalong the rod or shaft 70 into the position shown in Fig. 12, andreleasing it from the arm 33. The timing train thereupon starts, and,what is of great importance, the sleeve 72 wedges itself onto thetapered portion 71 of the rod or shaft,

and preventing the rebound of the sleeve with the consequent liabilityof stopping the timing train.

As my invention relates to a type of device that is intricate incharacter, I have necessarily described the preferred embodiment thereofsomewhat in detail. It is to be understood however, that I may vary theconstruction and arrangement of the elements constituting my inventionwithin considerably wide limits without departing from the spiritthereof.

My invention is further described and dcfined in the form of claims asfollows:

1. In a time fuse, the combination of a base,'a timing train mountedthereon, a firing pin, controlled by said timing train, asafety deviceoperable only by centrifugal force, said device being located in thebase and in the path of movement of the firing pin, and a lock for saidplate normallyin the path of movement of the plate, and movable out o-fsaid path by the shock of firing.

2. In a time fuse, the combination of a base, a timing train mountedthereon, a firing pin, operated by said timing train, a primer locatedin the base and in the path of movement of the firing pin, a ivotallymounted plate in said base, norma interposed between the primer and thefir1ng pin, and movable out of said position bycentrifugal force, and alock for said plate operable to release the plate by the shock of 3. Asafety device for fuses, comprising a base, a movable plate, engagingthe plate and holding it in operative position, a tapered pin, acircumferential groove therein near one end of said pin, a spring ringin said groove engagin the base and normally holding the pin in t e pathof movement of the plate, and means cooperating with the tapered pinafter the movement thereof to maintain the pin out of the path ofmovement of the plate. I

4. In a mechanical time fuse for detonating the explosive charge of ashell, including a timing train, a central staff therefor taperedintermediate its ends, a hub, mounted on said staff and having a tapercorresponding to the taper thereon, said hub being normally rotatable onsaid stafi, a gear wheel fixed on the hub and connected to the timingtrain, and a setting plate fixed to thestafi' and by means of which thetiming 0 eration of the train may be varied, said hu being forced ontothe taper of the staff by the shock of firing to couple the settingplate to the timing train.

5. Safety setting means for time fuses comprising a timing train, arotatable plate connected therewith, a firing notch in said plate,settin means including a depending spring comp etely spanning saidnotch, and means for operating the spring to rotate the setting plate tovary the setting of the timing train.

6. A mechanical time fuse for detonating the explosive charge ofa shell,includinga timing train, a setting plate therefor, a setting cap forrotating said late relatively to the timing train to vary t e time ofdetonation of the charge, a spring lever rigidly attached at one end tothe interior of the setting cap, cooperating means on the free end ofthe spring lever and on the periphery of the setting plate, for couplingsaid plate and cap together during the setting operation, and a slidingweight on the s ringlever, slidable toward the free end t ereof on theshock of firing, to allow the free end of the spring lever to moveoutwardlg to free the cap from the plate.

7. mechanical time fuse for detonating the explosive charge of a shellhaving, in combination, a timing train, a rotatable element therein, anarm, rigidly attached to the rotatable element and rotatable therewith,and an arm attached at one end to a stationary part of the timing train,a weight attached to the free end of said arm, the free end of said armlying normally in the path of movement of the rotatable element, thefree end of said arm being displaced by the shock of firing to free therotatable element and allow the starting of the timing train.

8. A mechanical time fuse for detonating the explosive charge of a shellhaving, in combination, a timmg train, a rotatable element therein, anarm, rigidly attached to the rotatable element and rotatable therewith,and an arm of non-spring metal attached at one end to a stationary partof the timing train, a weight attached to the free end of the said arm,the free end of said arm lying normally i@ the path of movement of therotatable element and being displaced by the shock of firing to free therotatable element and allow the starting of the timing train.

9. A mechanical time fuse for detonating'the explosive charge of a shellhaving in combination, a timing train, a rotatable element therein, anarm rigidly attached to the rotatable element and rotatable therewith,and an arm of non-spring metal attached at one end to a stationary partof the timing train, a weight attached to the free end of the said arm,the free end of said arm lying normall in the path of movement of therotatab e element and being permanently displaced'by the shock of firingto free the rotatable element and allow the starting of the timingtrain.

10. A mechanical time fuse for detonating the explosive charge of ashell having, in combination, a timing train, a firing pin, releasemeans for said firing pin associated with the timing train and operablethereby to release the firing pin after a predetermined length of time,means associated with said timing train to vary the time of operation ofthe firin pin at will, a safety device operable on t e shock of firingto start the'timing train in motion, and a second safety device,operable by centrifugal force to clear a path for the firing pin afterits release.

11. A safety device for fuses, comprising a base, a plate movableadjacent thereto, a tapered recess in said base, a pin tapered tocorrespond with the tapered recess, a circumferential groove in said pinnear one end thereof, a sprmg ring in said groove en aging the face ofthe base and normally ho ding the pin in the path of movement of theplate, the inertia of said pin operating, on the shock of firing, tomove the pin out of the path of movement of the plate and intoengagement with the tapered recess in the base.

' 12. A safety device for fuses, comprising a base, a plate pivotallymounted thereon, a recess in said base and tapered at the bottom, a pintapered to correspond with the tapered portion of the recess, acircumferential groove in said pin near the end remote from the taperedportion, a spring ring in said groove engaging the face of the base andnormally holding, the grooved end of the pin in the path of movement ofthe pivotal plate, and the tapered portion out of engagement \viththetapered portion ofthe recess, the inertia of said pin operating, on theshock of firing, to move the pin out of the path of movement of theplate and into engagement with the tapered portion of the recess in thebase.

13. Asafety device for fuses, comprising a base, a plate pivotallymounted thereon,

a recess in said base, a pin slidably mounted in said recess, means forholding one end of said pin out of said recess and in the path ofmovement of the pivoted plate, said pin operable on the shock of firingto be released from the holding means and to move into said recess outof the path of movement of said pivoted plate, and means on the pin andat the bottom of the recess for holding the pin in its operatedposition.

In testimony whereof, I have signed my name to this specification, inthe presence of two subscribing witnesses.

FREDRIOK WV. BOLD.

W'itnesses:

\VILLIaM H. NEAGLE, JAMEs R. HODDER.

